0.4.0

AirSensor2 0.4.0

Updated to handle changes in upstream packages:

• MazamaCoreUtils 0.4.15 => 0.5.1
• MazamaSpatialUtils 0.8.5 => 0.8.6
• MazamaLocationUtils 0.3.8 => 0.4.1
• MazamaTimeSeries 0.2.13 => 0.2.15
• AirMonitor 0.3.11 => 0.3.12

The breaking change that precipitated this was the change from 'zip' to
'postalCode' in the core metadata used by MazamaLocationUtils. For
backwards compatibility, all functions that work with metadata will guarantee
that both 'zip' and 'postalCode' exist. These include:

• Clarity_enhanceRawSynopticData()
• Clarity_createAllOpenMonitors()
• Clarity_createOpenMonitor()
• PurpleAir_createNewMonitor()
• pas_createNew()
• pas_enhanceRawData()
• pat_createNew()